The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory captions and links exemplifying features within the Earth system. The community is invited to contribute digital imagery, short captions and relevant links.

Pawnee Buttes

Pawnee Buttes, located in northeastern Colorado, are remnants of the White River Formation of the Oligocene Epoch. This is a portion of the same formation found in Badlands National Park in South Dakota. There are abundant fossils in the buttes and in the badlands around the buttes as well. Fossils shown include a jaw with teeth, possibly an oreodont (left insert), a turtle (middle insert), and a limb bone (right insert). The bone has changed little over the eons, except it's now stained with psilomelane, a manganese mineral.